Manufacture thereof



Patented June 1, 1943 DERIVATIVES F TROPIC ACID AMIDE AND MANUFACTURE THEREOF Wilhelm VVenner, Basel, Switzerland, assigncr to Hoffmann-La Roche Inc., Nutley, N. 5., a corporation of New Jersey No Drawing. Application June 26, 1939,, Serial No. 281,269. In Germany July 7, 1938 3 Claims.

The need for an effective choleretic has become more and more evident in recent years since it has been established that by increasing the secretion of bile, illnesses of the liver and obtained. The amines employed are also'best used in solution in water or in an organic solvent. The acetyl group is split off by treatment with alkalis or acids from the resulting O-acetyl tropic bile ducts can be favourably influenced. A num- 5 acid amides substituted in the amido group.

ber of cholagogic preparations have in fact al- Tropic acid amide and its neutral N-substiready been placed on the market. The better tuted derivatives are colourless compounds. The known among them contain as active sublower members of the series arecrystalline, the stances bile acid derivatives, podophyllin, as well higher members mostly liquids. They are to as extracts from plants (6, g. radish extract). be employed as choleretics. The examination Extracts from liver and gall bladder have also of the cholagogic action was carried out in acbeen employed as choleretics. cordance with Grabes process (Archiv fiir ex- It has now been found that tropic acid amide perimentelle Pathologie und Pharmakologie, vol. and its neutral N-substituted derivatives possess 176, year 1934, page 673). According to this a strong cholagogic action. method the gall secretion in the narcotised rat is Only tropic acid amide has been described in first determined over a period of 2 hours, the the literature up to the present (Annalen der preparation to be examined then administered Chemie, vol. 389, year 1912, page 111). This by means of a stomach tube, and the ensuing was obtained through the following intermediate change in the gall secretion observed. stages: Tropic acid, atropic acid, [3-bIO1I'10-a- The comparison of tropic acid dimethyl amide phenyl propionic acid. The manufacture of with desoxycholic acid, whose choleretic' action atropic acid as well as of B-blOIllO-ot-Dhfil'lYl is described in the literature (Biochemi'sche propionic acid does not proceed satisfactorily Zeitschrift, vol. 130, year 1922, page 556; Zeitbecause the formation of by-products cannot be schrift fur die gesamte experimentelle Medizin, avoided (Annalen der Chemie, vol. 209, year vol. 30, year 1922, p 423), Clearly Shows the 1881, page 12, paragraph 4). Likewise, the superiority of t e ew C as Of COIIIDOHHCISJ transformation of s-bromo-a-phenyl propionic acid into tropic acid amide can only be carried No.0fdropsofbilc out in poor yield, since atropic acid as well as perhour Change atrolactic acid and styrol occur as by-products Dow in Di (Annalen der Chemie, vol. 115, year 1860, page Preparation N6. ni jk g f g 159; vol. 209, year 1881, page 11). This process tion f ti f value cannot therefore be taken into consideration for $5,? $535 the technical synthesis of tropic acid amide.

The disadvantages described can be avoided if Tropic acirl 1 50 s 13 +625- ti'opic acid amide is obtained by allowing amg il i glgthyl monia to act on O-acetyl tropic acid chloride. g0 17 2 The ammonia may be employed in aqueous solu- E g3 12 tion or in a suitable organic solvent, such as g is is 2!; benzene, toluene, ether, chloroform, petroleum ether. O-acetyl tropic acid amide is obtained 8 ig 1:22 in very good yield. By treating this compound ll 25 13 .0 -"l with acids or alkalis under suitable conditions, 12 25 16 25 the acetyl group is split 01?. 5 Despxycholic 13 1g 12 -20 acid 14 50 10 12 20 If amines, e. g., aliphatic and aromatic primary 15 50 9 11 +22 and secondary amines, piperidine and its C-sub- 16 15 19 +2? stitution derivatives, aralkyl amines, cycloalkyl 17 25 9 s .11 amines, are caused to act on O-acetyl tropic acid i3 2' chloride in the same manner, the corresponding 50 20 25 19 14 I substituted amides of O-acetyl tropic acid are Example 1 45 parts by weight of O-acetyl tropic acid chloride (Berichte der Deutschen Chemischen Gesellschaft, vol. 41, year 1908, page 730) are added dropwise to 45 parts by weight of aqueous ammonia (25 per cent) while stirring and keeping the temperature at 20 C. by external cooling. The O-acetyl tropic acid amide formed is separated as a solid. It is sucked on and transformed into tropic acid amide by heating with 200 parts by Weight of a 4 per cent solution of caustic soda. tropic acid amide has a melting point of 169 C. The yield amounts to over 70 per cent of the theoretical.

Example 2 45 parts by weight of O-acetyl tropic acid chloride are added dropwise to 56 parts by Weight of aqueous ethylamine solution (33 per cent) while stirring, the temperature being kept at After recrystallisation from Water,

30 C. The reaction mixture i extracted with benzene. After evaporation of the benzene, about parts by weight of crude O-acetyl tropic acid ethylamide are Obtained. By short heating with a dilute solution of caustic soda the acetyl group is split off and tropic acid ethylamide of melting point 129 C. is obtained. The yield is about 80 per cent of the theoretical.

If allylamine is used instead of ethylamine, the above reaction produces tropic acid allyl amide melting at 1 0 C.

Example 3 parts by weight of O-acetyl tropic acid chloride are added drop by drop to parts by weight of aqueous dimethylamine solution (32 per cent) while stirring and cooling with ice. By extraction with benzene, 44 parts by weight of O-acetyl tropic acid dimethyl amide of melting point 68 C. are obtained. By heating with a 12 per cent solution of caustic soda, the acetyl group is removed and 30 parts by weight of tropic acid dimethyl amide melting at 96 C. are obtained.

Example 4 45 parts by weight of O-acetyl tropic acid chloride are dissolved in 100 parts by weight of chloreform and added dropwise to 30 parts by weight of diethylamine in 100 parts by weight of chloroform while stirring and cooling. The solution is evaporated to dryness and the residue treated with water and benzene. The benzene solution is separated and evaporated to dryness. The residue is left to stand with a mixture of 200 parts by weight of methanol and 40 parts by weight of concentrated hydrochloric acid at room temperature for 2 days. The mixture is then neutralised and evaporated to dryness. Tropic acid diethylamide of melting point 84 C. is obtained.

Example 5 45 parts by weight of O-acetyl tropic acid chloride are dissolved in 120 parts by weight of is left to stand overnight.

with water and dilute hydrochloric acid. Thev benzene and added dropwise to a. solution of 52 Example 6 15 parts by weight of O-acetyl tropic acid chloride are added dropwise to a solution of 40 parts by weight of piperidine in 200 parts by weight of benzene while stirring and cooling. The reaction mixture is extracted with water and evaporated to dryness. O-acetyl tropic acid piperidide of melting point 83 C. i obtained. By saponification with aqueous alcoholic alkali, .tropic acid piperidide of melting point 102 C. is obtained in a yield of per cent.

Example 7 25 parts by weight of O-acetyl tropic acid chloride are dissolved in parts by weight of benzene and added to a solution of 30 parts by weight of aniline in 100 parts by weight of benzene while stirring and cooling. The reaction mixture is extracted with water. After concentration, 40 parts by weight of O-acetyl tropic acid anilide melting at 131 C. are crystallised from the benzene solution. Saponification in 80 per cent ethyl alcohol with a 10 per cent solution of caustic soda at 70 C. yields tropic acid anilide in a yield of 80 per cent. The anilide crystallises from benzene in needles melting at- Example 8 25 parts by weight of O-acetyl tropic acid' chloride are dissolved in 100 parts by weight of toluene and the solution added dropwise to a solution of 35 part by weight of benzylamine in 300 parts by weight of toluene while cooling.

of alcohol and addition of the calculated quantity of a 20 per cent aqueous-solution of caustic soda at about 10" C. Tropic acid benzylamide is isolated by evaporation of the solution or by addition of water. By crystallisation from benzene it is obtained in pure form of melting point Example 9 20 parts by weight of tropic acid are transformed into O-acetyl tropic acid chloride in the usual manner. The O-acetyl tropic acid chloride is dissolved in 100 parts by weight of benzene and the solution added dropwise to a cooled solutionof 22 parts by weight of morpholine in 100 parts by weight of benzene while stirring. The mixture It is then extracted benzene solution is evaporated. The remaining oil is dissolved in 100 parts by weight of alcohol. 36 parts by Weight of a 10 per cent solution of caustic soda are added dropwise to the solution while stirring and keeping at moderate temperature. After 2 hours the reaction mixture is acidifled and evaporated to dryness. The residue is extracted with boiling benzene. tropic acid morpholide crystallises from the concentrated benzene extract. By recrystallisation from benzene petroleum-ether, the compound is obtained in colourless needles melting at 91 C. The yield amounts to about 18 parts by wcigl lt.

Example 10 O-acetyl tropic acid chloride, obtained in the usual manner from 25 parts by Weight of tropic On cooling,

acid, is dissolved in 100 parts by weight of benzene and the solution added dropwise to a solution of 55 parts by weight of veratrylamine (3,4- dimethoxy benzylamine) in 100 parts by weight of benzene while stirring and cooling. After 3 hours the reaction mixture is diluted with 200 parts by weight of Water. The undissolved product (veratrylamine hydrochloride) is sucked off. The filtrate consists of 2 layers. The upper be-nzene layer is separated and evaporated. O-acetyl tropic acid veratrylamide remains as a crystalline compound melting at 102 C. It is dissolved in alcohol and a 10 per cent solution of caustic soda added until the mixture shows remaining alkaline reaction. After 1 hour the product is acidified and evaporated to dryness in vacuo. The residue is crystallised from dilute alcohol or from benzene. About 30 parts by Weight of tropic acid veratrylamide are obtained in colourless needles of melting point 120 C.

I claim: 1. Derivatives of tropic acid amide of the formula wherein R is selected from the group consisting of hydrogen and aralkyl, and R" is an aralkyl group.

2. Tropic acid benzylamide.

3. Process for the manufacture of tropic acid benzylamide, comprising reacting O-acetyl tropic acid chloride with benzylamine and splitting off the acetyl group from the O-acetyl tropic acid benzylamide formed by means of a hydrolising agent.

WILHELM WENNER. 

